The body of research on the antecedent risk and protective factors for drug use includes a large number of longitudinal panel studies covering various segments of the life course and a diversity of variables, and a larger number of supporting cross sectional studies. This research is especially significant for understanding the etiology of drug use from a developmental perspective and for designing risk focused programs for the prevention of adolescent and adult drug abuse. The complexity and diversity of this research, however, makes the task of synthesizing and integrating its empirical findings quite difficult using traditional approaches. This project proposes to use advanced metaanalysis techniques to achieve a quantitative integration of the research findings that bear on three issues: (1) The convergence of risk factors, of drug use profiles, and of other associated problem behaviors at various life stages; that is, how much intercorrelation or co-occurrence there is within and among these sets of variables at different developmental periods. (2) The relative independent strength of association of different categories of antecedent risk variables with subsequent drug use and how those associations vary by life stage and type of-rug used. Particular attention will be paid to the relationship of subsequent drug use to early tobacco, alcohol, or marijuana use (gateway drugs) and the related issue of age of onset of first drug use. (3) The generalizability of the various relationships found on the above issues across gender, ethnic and socioeconomic groups, populations sampled, and historical cohorts.